Electronic accumulator



Jan. 13,1953 R E. MUMMA 2,625,326"

ELECTRONIC ACCUMULATOR Filed May 25, 1950 HUNDREDS ORDER TEN'S ORDER NVENTOR ROBERT E. MUMMA HIS ATTORNEY Patented Jan. 13, 1953 ELECTRONIC ACCUMULATOR Robert E. Mumma, Dayton, Ohio, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Application May 25, 1950, Serial N 0. 164,107

. 3 Claims. (crass-92) This invention relates to a novel electronic accumulator and in particular to an accumulator operable in response to positive input impulses, which accumulator includes a simplified gaseous electron tube counting ring in each denominational order operable step by step in response to negative stepping impulses and includes tens transfer means between adjacent orders which are operable, when required, in response to the positive input impulses.

In the novel accumulator, each denominational order includes an entry tube, a tens transfer tube. and a tube for each of the digits that may be registered, the digit-representing tubes being connected in a simplified ring which is operated in step-by-step fashion in response to negative stepping impulses applied to the tubes through the extinguishing circuit for the ring. The tens transfer tube is coupled to the 9 digitrepresenting tube to be primed thereby when the 9 tube is conducting and has each of the positive input impulses impressed thereon to be operated thereby whenever primed. The entry tube has positive input impulses impressed thereon from an input impulse generator and, in orders other than the units order, from the next lower 2 cumulator for accumulating amounts in the decimal notation.

In this disclosure, the various potentials are given with reference to ground. It is not intended that the invention be limited to the'use of the particular potentials and values of resistance and capacitance given in the following description, because the potentials applied to the various elements of the tubes are merely selected as convenient potentials for the disclosure, and the circuit elements of resistance and capacitance I correspond in relative value to the potentials order transfer tube and converts these impulses into negative stepping impulses of desired shape for operating the ring.

It is an object of the invention to provide a simplified accumulator which is responsive to positive input impulses and which utilizes in each order a simplified counting ring operable by negative, impulses, together with transfer means operable in response to positive impulses.

It is another object of this invention to provide an accumulator which is made up of digit representing gaseous electron discharge device counting rings that are operable in response to negative stepping impulses and tens transfer discharge devices that are controlled from the rings and are operable in response to positive impulses.

With these and incidental objects in view, the invention includes certain novel features of construction and combinations of parts, a preferred form or embodiment of which is hereinafter de scribed with reference to the drawing which accompanies and forms a part of this specification.

The drawing shows a circuit diagram of two orders of an accumulator with associated controls, certain of the tubes in each order being omitted from the drawing for clarity.

The embodiment of the invention which will be used to explain the invention will be that of an acchosen. It is obvious that other tubes which are equivalent to the type to be specified and other potentials may be used and the values of the circuit elements adjusted accordingly to maintain the proper relation between the various parts of the circuit. Throughout the drawing, the cathode heater elements are shown conventionally.

The drawing shows the units and tens denominational orders of the novel accumulator. Each order includes an entry tube, an electron tube counting ring containing a tube for each of the digits 0 and 1 through 9, and a transfer tube. Since the circuits to and between the tubes of the ring are the same, tubes 2 through 7 of the ring and their related circuits have been omitted in the circuit diagram, inasmuch as their operation and arrangement will be clear from the circuits which are shown for tubes O," 1, 8, and 9. Further, since the several orders are substantially alike, it is believed that an understanding of the construction and operation of the accumulator will be clear from the detailed description of one of the orders.

The simplified ring which is used as a component of each denominational order of the novel accumulator is fully disclosed in the copending Desch and Mumma application, Serial No. 164,108, which was filed on May 25, 1950, and which issued as Patent No. 2,598,764 on June 3, 1952. In this ring, the tubes for the digits "0 and 1 through "9 are connected for step-bystep sequential operation in response to negative impulses applied to the ring. The tubes used in the ring of the disclosed embodiment are gaseous tetrodes such as tubes sold by General Electric Company under the .type designation GL5663.

Anode potential of volts is applied from terminal as over positive potential supply conductor 3: to the anodes of the tubes of the ring.

The cathodes and control grids of the tubes of the ring are supplied with negative potential from potential dividers which are supplied with a potential of -75 volts from terminal 32. The potential divider for supplying the potential to the cathode of the tube and the control grid of the 1 tube is representative and extends from point 33 on negative potential supply conductor 34, which is connected to terminal 32, thence over resistor 35 of 1.5 megohms, point 36, resistor 3'! of 2.7 megohms, points 38 and 39, and resistor 40 of 22,000 ohms to ground. The cathode of the 0 tube is connected to this circuit at point 39, and the control grid of the 1" tube is connected at point 36, so that the control grid will normally have a more negative Potential than the cathode. Since similar potential dividers are provided to supply cathode and control grid potentials to the various other tubes, the control grid of each tube normally'will be sufficiently negative with respect to its cathode to prevent conduction. The connection of the cathode of one tube of the ring and the control grid of the next tube in the ring to the same potential divider enables the tubes to be connected in a ring for sequential operation.

It is to be noted that, when a tube is not conducting, its cathode will be given a potential slightly negative with respect to ground; however, when the tube is conducting, the cathode will also be conductively coupled to the anode, which will cause the potential of the cathode to become highly positive. This potential change of the cathode of a conducting tube is reflected, through its potential divider, on the control grid of the next tube in the chain and will reduce the bias on that tube, or prime it, to make it more responsive than any other tube of the ring to an impulse applied to the ring. The shield grid of each of the tubes is directly connected to its cathode.

Due to the fact that the tubes of the ring are gaseous electron tubes, an extinguishing'circuit is provided to enable conduction commencing in a tube to extinguish any previously conducting tube. The extinguishing circuit consists of parallel capacitative couplings as by capacitors as 45 of 500 micro-microfarads and over resistors as 46 of 4,700 ohms for each tube from its cathode to a common point or conductor 4!. The extinguishing action in this circuit is as follows. When a tube is conducting, its cathode will be at a positive potential which is less than anode potential by the amount of drop across the conducting tube. This will cause the capacitor as as associated with the cathode of the conducting tube to be charged so as to have a potential drop thereacross corresponding to the differences in potential between the cathode and that of the common point or conductor 41, which is also conpied-to the other cathodes having negative potential. As-the next tube in the ring is fired, its cathode potential rise will be impressed as a positive impulse on the common conductor 41 through its coupling thereto, and this potential impulse on the common conductor will be impressed'through the capacitative couplings to the cathodes of the other tubes of the ring. This positive pulse will have the effect of merely increasing the bias on the non-conducting tubes, but, in the case of the previously-conducting tube, whose cathode is already at a high positive potential, it will be effective to momentarily drive the cathode potential more positive than the anode potential and cause conduction to cease in this tube. Accordingly, the firing of any tube in the ring will be efiective to impress a positive impulse on the extinguishing circuit and thereby extinguish any previously-conducting tube.

In the novel accumulator, the extinguishing circuit for the ring is also used as the input circuit through which impulses can be impressed on the ring to cause the step-by-step operation of the tubes therein.

Negative stepping impulses of steep wave front and of short duration are applied to the common point or conductor 47 and are impressed on all the cathodes over the parallel couplings including the resistors as 46 and capacitors as 45. These negative impulses on the cathodes will tend tocause the cathodes and the control grids connected thereto tobecome more negative, but these negative excursions will be ineffective to cause any but the primed tube to be fired. It will be recalled that, in the case of the conducting tube, conduction in the tube will cause its cathode to become positive, which in turn reduces the Mason the control grid of the next tube of the ring and makes the control grid potential only slightly more negative than its related cathode. When the negative impulse is applied to the cathodes through the extinguishing circuit, itwillhave very little effect on the cathode of the conducting tube due to the conduction in the tube and consequently will cause very little change in the potential of the control grid of the primed tube which is connected thereto. This negative impulse will have a greater efiect on the cathodes of the non-conducting tubes and will make the cathode of the primed tube sufiiciently more negative relative to its control grid that the bias on the control grid of this tube is overcome and the tube will fire and become conducting;

The application of the negative stepping impluses to the extinguishing circuit will not afiect the operation of the circuit to extinguish a previously-conducting tube upon the firing of another tube in the ring because the negative impulse has little effect on the potential of the cathode of the conducting tube and because the amount of the positive potential rise which is applied tothe cathode of the conducting tube as asubsequent tube is fired, when added to the already high positive potential of the cathode due to conduction in the tube, is much more than that necessary to overcome the drop across the previously-conducting tube and cause the" cathode potential to become more positive than the anode potential, thereby extinguishing the conduction in the previously-conducting tube.

In order that the accumulator, which responds to positive input impulses, can utilize the simplifiedring, an entry tube is provided for each denominational orde'r'to invert the input impulses and provide the negativestepping impulses of the desired form. The negative stepping impulses are applied to conductor 41 from the entry tube;

which is designated E1 in the units order. This tube is a gaseous tetrode of the type GL5663,

previously described. The anode of tube E1 is connected over point 50 and resistor 51 of 100,000

ohms to the +l05-volt positive potential supply conductor 3|. Point 50 is coupled to ground over a capacitor 52 of .001 microfarad to enable the tube to be extinguished automatically after each conduction therein. Point 50 is also coupled over a capacitor 53 of .0015 microfarad to conductor 41 to enable the anode potential drop, as the tube conducts, to be applied'as a negative stepping impulse to conductor 41L The shield grid and cathode of entry tube E1 are directly'connectedto ground, and the con i trol grid is supplied with a negative bias over point 54 and resistor 55 of l megohm from a tap 55 on resistor 51 of 25,000 ohms, which is connected between the -75-volt potential conductor 34 and ground.

The point 54 in the control grid circuit of the entry tube E1 is coupled over a capacitor 58 of 25 micro-microfarads to the units order input conductor 59, on which the required number of positive input impulses, according to the entry to be made, are impressed by a suitable impulse generator; for instance, one of the type disclosed in the Mumma Patent No. 2,404,739. Each of the impulses on the input conductor 59 will cause the entry tube E1 to conduct momentarily to produce a negative stepping impulse on conductor 41 to cause the primed tube of the ring to be fired.

The tens order of the accumulator is constituted and operates the same as the unit order described above. Positive impulses on the tens order input conductor 65 cause the tens order entry tube E2 to be fired and impress negative stepping impulses on the common conductor 66 of the extinguishing circuit for the ring of digitrepresenting tubes of the tens order.

The accumulator can be set in its zerorepresenting conditioninitially, or at any time it is desired to reset the accumulator to zero, merely by momentarily closing reset switches as 80 and BI to remove the bias from the tubes of the I rings by connecting the control grids of these tubes to their cathodes.

A transfer tube is provided for each order to cause an entry of one to be made in a higher order each time the lower order exceeds its capacity. The transfer tube T1, which is controlled by the units order and causes an entry of one to be made in the tens order, is of the GL5663 type, previously noted herein.

The anode of transfer tube T is connected to the +105-volt potential supply conductor 3!.

The control grid of the transfer tube T1 is given a normal negative bias by being connected at point 6'! in a potential divider network which extends from the -'75-volt negative potential supply conductor 34 to ground over resistor 68 of 1.5 megohms, point 61, resistor 69 of 2.7 megohms, and the cathode resistor 10 of 22,000 ohms of the 9 tube. The inclusion of resistor ID in this potential divider enables the 9 tube, when conducting, to reduce the bias on the trans: fer tube T1 in the same manner as explained earlier in connection with the priming of the tubes of the ring. The control grid of the transfer tube T1 is also coupled over a capacitor H of 25 micro-microfarads to the units order input I conductor 59 and has each of the positive input impulses impressed thereon. The normal bias on the grid is sufiicient to prevent these impulses from firing the transfer tube; however, when the 9 tube is conducting, it will prime the transfer tube, so that the positive input impulse on conductor 59, which operates the entry tube E1 to cause the 0 tube to be fired, will also be effective to fire the transfer tube T1 to cause a carry to be effected.

The cathode of the transfer tube T1 is connected to ground over point and resistor 16 of 100,000 ohms and capacitor 71 of 50 micro-microfarads in parallel, point I5 in this circuit being connected over conductor 18 to the input conductor 65 of the tens denominational order. The circuits in which the transfer tube T1 is connected will cause the tube to be extinguished automatically each time it has conducted. Eachtime the transfer tube T1 conducts, its cathode potential excursion will be impressed, over conductor 18, on the input conductor 65 as a positive impulse to operate the transfer tube T2 if necessary and also to cause the entry tube E2 for the tens order to operate and furnish a stepping impulse to the ring of digit-representing tubes of that order.

The transfer tube T2 for the tens order, which is similar to the transfer tube T1, is primed when the 9 tube of the tens order conducts and is fired by the next impulse on the input conductor of the tens order in the same manner as explained above in connection with transfer tube T1. The cathode of transfer tube T2 can also be connected over conductor 8| to the input conductor of the next higher order to enable entries to be made therein.

It is to be understood that entries are made in the orders of the accumulator in succession in the embodiment shown only because the transfer mechanism used is of the immediately acting type. Where a delayed transfer type of transfer mechanism is used, entries can be made simultaneously in the various orders of the accumulator.

It is clear from the foregoing description that the novel accumulator, which operates in response to positive input impulses, can utilize simplified counting rings which operate in response to negative stepping impulses together with transfer mechanism which operates in response to positive impulses. The novel arrangement by which the simplified rin can be used in the accumulator and be integrated with the other components thereof provides a much simpler accumulator of this type than was possible heretofore.

While the form of apparatus herein shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the one form or embodiment disclosed herein, for it is susceptible of embodiment in various other forms.

What is claimed is:

1. In an accumulator which is operable in response to positive input impulses and which has in each denominational order thereof the combination of a plurality of electron discharge devices; a circuit network for supplying operating potential to said devices and for connecting the devices in a ring for sequential operation; a further circuit connecting the devices for mutual extinguishing action whereby conduction beginning in a device will extinguish a previouslyconducting device, said further circuit also serving as an input circuit by which negative stepping impulses can be impressed on the devices of the ring to cause their sequential operation; an entry electron discharge device; circuits to supply operating potential to the entry device and to enable th entry device to impress a negative stepping impulse on said further circuit for each positive impulse impressed on the entry device; a. tens transfer electron discharge device; circuits for supplying operating potential to the tens transfer device and for producing a positive impulse each time the transfer device operates; a priming circuit connecting one of the devices of the ring to the transfer device to prime the transfer device for operation whenever said one device of the ring conducts; and means to impress positive input impulses on the entry device and the transfer device to cause the sequential o'peration of: the devices of thering andthe operation of thetransfer device'when it has been primed.

2. In an accumulatoriwhich is operable in response to" positive input impulses and which has in. each denominational order thereof the-combination of a plurality of electron discharge devices, each device having at least an anode, acathode, and means to control conduction therebetween; a circuit network for supplying operating potential to said devices and for connecting thedevices, cathode to control means, in a. ring for sequential operation; a further circuit electrostatically connecting the cathodes of the devices together for mutual extinguishing action whereby conduction beginning in a, device will extinguish a-previously-conducting device, said further circuit also serving as an input circuit by which negativeistepping impulses can be impressed on the cathodes of the devices of the ring to cause their sequential operation; an entry electron dis-- charge device having at least an anode, a cathode, and means to control conduction therebetween; circuitsto supply operating'potential to the entry device and to enable the entry device to impress a negative stepping impulse on said further circuit each time the entry device responds to a positive impulse impressed on the control means thereof; atens transfer electron discharge device having at least an anode, a cathode, and meansto control conduction therebetween; circuits for supplying operating potential to the tens transfer device and for producing a positive impulse each time thetransfer device operates;

apriming circuit connecting the cathode of one I of thedevices of the ring to the control means of the transfer device to prime the transfer device for operation whenever said one device of theringconducts; means to impress positive input impulses on the control means of the entry device and the transfer device to cause the sequential operation of the devices of the ring and the operationof the transfer device when it has been primed; and means connecting the transfer device of one order to the means to impress positive input impulses on the devices of the next higher order to enable tens transfer entries to be made in said next higher order.

3. In amulti-denominational accumulator operable in response to positive input impulses, the

combination of a plurality of digit-representing gaseous electron discharge devices for each denominational order; circuits for supplying operating potentials to the devices and for connectingthe digit-representing devices in each order in a ring for sequentialoperation in response; to

negative stepping impulses; a further circuit-for connecting the digit-representingdevicesin eachring together for mutual extinguishing, action=to enable conduction beginning in a device of the ring to cause any previously-conducting device of that ring to be extinguished; an electron discharge entry device for each denominational or-'- der; circuits for supplyingv operating potentialto the entry devices and enabling each entry de vice, as it operates, to produce a negative stepping impulse; means coupling the circuits for the entry devices to the further circuits in related denominational orders to impress the negative stepping impulses on the further circuits and thereby on the digit-representing devices of the rings to cause digit entries to be made therein as the entry devices operate; a positive impulse'input conductor for each denominational. order, to

impress digit-respresenting impulse on thator-.

der; means coupling the input conductor for any order to the entry device for that order to impresserates; control mean including a priming circuit from a selected device of the ring to thetransfer device of the same denominational orderfor rendering the transfer device operable in response to positive impulses when said selected device of the ring conducts; a coupling. from the input conductor of an order to its related transfer device to impress positive input impulses on the transfer device and cause its operation if it has been primed; and acoupling from the transfer device of one order to the input conductor of the next higher order to impress thepositive impulse produced by the transfer device on the input conductor of the next order to cause a tens transfer entry of a value of one to be made in that order.

ROBERT E. MUMMAl REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,442,428" Mumma June 1, 1948 2,484,115

Palmer Oct. 1-1, 1949 

